ACT科学推理样题解析

　　下面是ACT科学推理部分的样题，对ACT科学推理部分的题目，应对策略主要是审题，确定研究对象(以便排除与研究对象无关的干扰选项);分析研究对象之间的关系，掌握科学的研究分析原则。

　　Passage IV

　　Three studies were conducted to examine the relation shop between ants and acacia trees they inhabit.

　　解题的第一步首先是审题。第一步就是要读最前边的一段论述性文字，在这一步骤中，重点关注这篇文章的主体，也就是主要研究对象，这里当然也就是ants and acacia trees they inhabit。以下每个实验研究的介绍处理方法一样，扫读，重点关注其分别的次级研究对象就足够了。强调一点，次级研究对象一定是紧密围绕着主要研究对象的。以上就是我们对审题的要求。

　　Study 1

　　Table 1 shows the results of a comparison between a species of acacia tree that is inhabited by ants (ant trees) and a species that is not inhabited by ants (non-ant trees).

　　Table 1

　　Ant trees Non-ant trees

　　Leaves bitter-tasting chemicals absent

　　protein-bodies present bitter-tasting chemicals present

　　protein-bodies absent

　　Thorns specialized hollow thorns on stems no specialized thorns

　　Ants specific ant species living in thorns no ants living on trees

　　Exrafloral nectaries present absent

　　Trunk surrounded by bare ground surrounded by many other plants

　　﹡Nectar-producing (sugar-producing) structures located outside the flowers

　　Study 2

　　Table 2 shows the results of a comparison between acacia ant and a closely related ant species that does not inhabit acacia trees.

　　Table 2

　　Acacia ants Non-acacia ants

　　Aggressiveness very aggressive very aggressive

　　Active periods active day and night active during daylight only

　　Diet protein-bodies

　　nectar do not eat living plants

　　Nest site only in the thorns of ant trees in the ground

　　Study 3

　　Acacia trees were divided into three groups. Acacia ants were removed from the trees in group A, but were left on the trees in Group B. Group C consisted of a species of non-ant acacia tree. All the trees were initially healthy and of similar size, the number of trees still alive in each group 300 days after the start of the study is shown in Table 3

　　Table 3

　　Group A Group B Group C

　　Day alive dead alive dead alive dead

　　1

　　300 38

　　10 0

　　28 39

　　28 0

　　11 40

　　30 0

　　10

　　Trees in Group A were killed by plant-eating insects and large mammals that ate the leaves on lower branches. There was no evidence that trees in Groups B and C were killed by grazing animals.